According to conventional practices, package boxes for export are individually made in accordance with the sizes and kinds of items accommodated thereinto, and alternatively, regular sizes of package boxes are made.
If items like fruits and vegetables are put in the regular sizes of package boxes in the conventional practices, however, a lot of time for packing them in the package boxes is needed due to given heights of the boxes, without having any damage to them.
So as to solve the above problems, multistage boxes have been proposed, and a variety of brackets and fastening members for fastening the neighboring multistage boxes have been accordingly disclosed. Korean Patent Application Laid-Open No. 10-2012-0028161 discloses folding type bracket for package box, thereby ensuring the fastening and rigidity of the multistage boxes, but, unfortunately, it needs a lot of time for fastening and separating the multistage boxes.
Further, Korean Patent No. 10-1099427 discloses folding type delivery assembling box, which is used when package boxes are collected.
The present invention is proposed to avoid the inconveniences in the fastening and separating processes of the multistage boxes suffered in Korean Patent No. 10-1121894 issued to the same applicant as this invention.
Moreover, there is a definite need for development of a new package box capable of easily discharging bulk freight (for example, grain, coal, and oil), bolts and nuts, and liquid therefrom.